Email language

I would be grateful for your advice regarding this topic / matter / material /.

After / careful / a lot / slight / consideration, we have decided not to go ahead with the conference given the current circumstances.

I would appreciate it if you could call me at your earliest / moment / as possible / convenience.

Unfortunately, we are unable to make a donation to your organisation due to budget / problem / limit / constraints /.

I can now confirm that the documents have been sent and should / arrive / reach / deliver / you within 10 working days.

I suggest that you  / contact / to contact / contacting / the client directly about a  renegotiation.

I am afraid something urgent has come  /up / along / out / and I won't be able to  / assist / go / attend the meeting.

We have taken special  / care / attention / caution / to make sure that the layout is exactly as you requested.

Regarding the documents you requested, I am / waiting / awaiting / requiring / the final approval from my supervisor.

Please confirm your decision / during / by / within / the next 24 hours.

I am / afraid / regret / unhappy / that we cannot / accept/ except / have any /  responsibility for the delay.

Once again, thank you for your quick / replying / response / reaction /

The documents will be emailed to you / until / by / within / the end of the day.

I sincerely / wish / hope / would like / that you will agree to participate in the upcoming conference.

We are / preparing / willing / want / to work with you to find a mutually beneficial solution.